In imaging systems, such as inkjet printers, electrophotographic printers, electrophotographic copiers, fax machines, or the like, it is important to accurately sense the quantity of media stored in a media input device such as a media tray. For efficient processing of imaging jobs, it is important that the imaging system determine if sufficient media remains in the input device to complete the imaging job. Therefore, a need exists for an accurate, low cost apparatus for determining the quantity of media in a media input device.